[PATCH 1/9] mtd: core: add nvmem_write support

From: Marco Felsch
Date: Mon Jul 01 2024 - 09:55:23 EST


The MTD framework does support the NVMEM framework already but only the
read support was implemented. This commit adds the write support if the
MTD device supports writing (MTD_WRITEABLE is set).

Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
---
drivers/mtd/mtdcore.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 724f917f91ba..dcd97e59425e 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -544,6 +544,20 @@ static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
return retlen == bytes ? 0 : -EIO;
}

+static int mtd_nvmem_reg_write(void *priv, unsigned int offset,
+ void *val, size_t bytes)
+{
+ struct mtd_info *mtd = priv;
+ size_t retlen;
+ int err;
+
+ err = mtd_write(mtd, offset, bytes, &retlen, val);
+ if (err && err != -EUCLEAN)
+ return err;
+
+ return retlen == bytes ? 0 : -EIO;
+}
+
static int mtd_nvmem_add(struct mtd_info *mtd)
{
struct device_node *node = mtd_get_of_node(mtd);
@@ -555,10 +569,11 @@ static int mtd_nvmem_add(struct mtd_info *mtd)
config.owner = THIS_MODULE;
config.add_legacy_fixed_of_cells = of_device_is_compatible(node, "nvmem-cells");
config.reg_read = mtd_nvmem_reg_read;
+ config.reg_write = mtd_nvmem_reg_write;
config.size = mtd->size;
config.word_size = 1;
config.stride = 1;
- config.read_only = true;
+ config.read_only = !(mtd->flags & MTD_WRITEABLE);
config.root_only = true;
config.ignore_wp = true;
config.priv = mtd;

--
2.39.2